]> bbs.cooldavid.org Git - net-next-2.6.git/blame - drivers/acpi/acpica/utxface.c
Merge branch 'pnp-log' into release
[net-next-2.6.git] / drivers / acpi / acpica / utxface.c
CommitLineData
1da177e4
LT
1/******************************************************************************
2 *
3 * Module Name: utxface - External interfaces for "global" ACPI functions
4 *
5 *****************************************************************************/
6
7/*
a8357b0c 8 * Copyright (C) 2000 - 2010, Intel Corp.
1da177e4
LT
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
1da177e4 44#include <acpi/acpi.h>
e2f7a777
LB
45#include "accommon.h"
46#include "acevents.h"
47#include "acnamesp.h"
48#include "acdebug.h"
49#include "actables.h"
1da177e4
LT
50
51#define _COMPONENT ACPI_UTILITIES
4be44fcd 52ACPI_MODULE_NAME("utxface")
1da177e4 53
e20a679b 54#ifndef ACPI_ASL_COMPILER
1da177e4
LT
55/*******************************************************************************
56 *
57 * FUNCTION: acpi_initialize_subsystem
58 *
59 * PARAMETERS: None
60 *
61 * RETURN: Status
62 *
63 * DESCRIPTION: Initializes all global variables. This is the first function
64 * called, so any early initialization belongs here.
65 *
66 ******************************************************************************/
dd272b57 67acpi_status __init acpi_initialize_subsystem(void)
1da177e4 68{
4be44fcd 69 acpi_status status;
44f6c012 70
b229cf92 71 ACPI_FUNCTION_TRACE(acpi_initialize_subsystem);
1da177e4 72
cb219bb6 73 acpi_gbl_startup_flags = ACPI_SUBSYSTEM_INITIALIZE;
4be44fcd 74 ACPI_DEBUG_EXEC(acpi_ut_init_stack_ptr_trace());
1da177e4 75
1da177e4
LT
76 /* Initialize the OS-Dependent layer */
77
4be44fcd
LB
78 status = acpi_os_initialize();
79 if (ACPI_FAILURE(status)) {
b8e4d893 80 ACPI_EXCEPTION((AE_INFO, status, "During OSL initialization"));
4be44fcd 81 return_ACPI_STATUS(status);
1da177e4
LT
82 }
83
73459f73
RM
84 /* Initialize all globals used by the subsystem */
85
b417d40b
YY
86 status = acpi_ut_init_globals();
87 if (ACPI_FAILURE(status)) {
88 ACPI_EXCEPTION((AE_INFO, status,
89 "During initialization of globals"));
90 return_ACPI_STATUS(status);
91 }
73459f73 92
1da177e4
LT
93 /* Create the default mutex objects */
94
4be44fcd
LB
95 status = acpi_ut_mutex_initialize();
96 if (ACPI_FAILURE(status)) {
b8e4d893
BM
97 ACPI_EXCEPTION((AE_INFO, status,
98 "During Global Mutex creation"));
4be44fcd 99 return_ACPI_STATUS(status);
1da177e4
LT
100 }
101
102 /*
103 * Initialize the namespace manager and
104 * the root of the namespace tree
105 */
4be44fcd
LB
106 status = acpi_ns_root_initialize();
107 if (ACPI_FAILURE(status)) {
b8e4d893
BM
108 ACPI_EXCEPTION((AE_INFO, status,
109 "During Namespace initialization"));
4be44fcd 110 return_ACPI_STATUS(status);
1da177e4
LT
111 }
112
b0ed7a91
LM
113 /* Initialize the global OSI interfaces list with the static names */
114
115 status = acpi_ut_initialize_interfaces();
116 if (ACPI_FAILURE(status)) {
117 ACPI_EXCEPTION((AE_INFO, status,
118 "During OSI interfaces initialization"));
119 return_ACPI_STATUS(status);
120 }
121
1da177e4
LT
122 /* If configured, initialize the AML debugger */
123
4be44fcd 124 ACPI_DEBUGGER_EXEC(status = acpi_db_initialize());
4be44fcd 125 return_ACPI_STATUS(status);
1da177e4
LT
126}
127
1da177e4
LT
128/*******************************************************************************
129 *
130 * FUNCTION: acpi_enable_subsystem
131 *
132 * PARAMETERS: Flags - Init/enable Options
133 *
134 * RETURN: Status
135 *
136 * DESCRIPTION: Completes the subsystem initialization including hardware.
137 * Puts system into ACPI mode if it isn't already.
138 *
139 ******************************************************************************/
4be44fcd 140acpi_status acpi_enable_subsystem(u32 flags)
1da177e4 141{
4be44fcd 142 acpi_status status = AE_OK;
1da177e4 143
b229cf92 144 ACPI_FUNCTION_TRACE(acpi_enable_subsystem);
1da177e4 145
1da177e4
LT
146 /* Enable ACPI mode */
147
148 if (!(flags & ACPI_NO_ACPI_ENABLE)) {
4be44fcd
LB
149 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
150 "[Init] Going into ACPI mode\n"));
1da177e4
LT
151
152 acpi_gbl_original_mode = acpi_hw_get_mode();
153
4be44fcd
LB
154 status = acpi_enable();
155 if (ACPI_FAILURE(status)) {
b229cf92 156 ACPI_WARNING((AE_INFO, "AcpiEnable failed"));
4be44fcd 157 return_ACPI_STATUS(status);
1da177e4
LT
158 }
159 }
160
009c4cbe
BM
161 /*
162 * Obtain a permanent mapping for the FACS. This is required for the
163 * Global Lock and the Firmware Waking Vector
164 */
165 status = acpi_tb_initialize_facs();
166 if (ACPI_FAILURE(status)) {
167 ACPI_WARNING((AE_INFO, "Could not map the FACS table"));
168 return_ACPI_STATUS(status);
169 }
170
1da177e4
LT
171 /*
172 * Install the default op_region handlers. These are installed unless
173 * other handlers have already been installed via the
174 * install_address_space_handler interface.
175 */
176 if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
4be44fcd
LB
177 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
178 "[Init] Installing default address space handlers\n"));
1da177e4 179
4be44fcd
LB
180 status = acpi_ev_install_region_handlers();
181 if (ACPI_FAILURE(status)) {
182 return_ACPI_STATUS(status);
1da177e4
LT
183 }
184 }
185
186 /*
187 * Initialize ACPI Event handling (Fixed and General Purpose)
188 *
96db255c
BM
189 * Note1: We must have the hardware and events initialized before we can
190 * execute any control methods safely. Any control method can require
191 * ACPI hardware support, so the hardware must be fully initialized before
192 * any method execution!
193 *
194 * Note2: Fixed events are initialized and enabled here. GPEs are
195 * initialized, but cannot be enabled until after the hardware is
196 * completely initialized (SCI and global_lock activated)
1da177e4
LT
197 */
198 if (!(flags & ACPI_NO_EVENT_INIT)) {
4be44fcd
LB
199 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
200 "[Init] Initializing ACPI events\n"));
1da177e4 201
4be44fcd
LB
202 status = acpi_ev_initialize_events();
203 if (ACPI_FAILURE(status)) {
204 return_ACPI_STATUS(status);
1da177e4
LT
205 }
206 }
207
96db255c
BM
208 /*
209 * Install the SCI handler and Global Lock handler. This completes the
210 * hardware initialization.
211 */
1da177e4 212 if (!(flags & ACPI_NO_HANDLER_INIT)) {
4be44fcd
LB
213 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
214 "[Init] Installing SCI/GL handlers\n"));
1da177e4 215
4be44fcd
LB
216 status = acpi_ev_install_xrupt_handlers();
217 if (ACPI_FAILURE(status)) {
218 return_ACPI_STATUS(status);
1da177e4
LT
219 }
220 }
221
4be44fcd 222 return_ACPI_STATUS(status);
1da177e4
LT
223}
224
8313524a
BM
225ACPI_EXPORT_SYMBOL(acpi_enable_subsystem)
226
1da177e4
LT
227/*******************************************************************************
228 *
229 * FUNCTION: acpi_initialize_objects
230 *
231 * PARAMETERS: Flags - Init/enable Options
232 *
233 * RETURN: Status
234 *
235 * DESCRIPTION: Completes namespace initialization by initializing device
236 * objects and executing AML code for Regions, buffers, etc.
237 *
238 ******************************************************************************/
4be44fcd 239acpi_status acpi_initialize_objects(u32 flags)
1da177e4 240{
4be44fcd 241 acpi_status status = AE_OK;
1da177e4 242
b229cf92 243 ACPI_FUNCTION_TRACE(acpi_initialize_objects);
1da177e4
LT
244
245 /*
246 * Run all _REG methods
247 *
96db255c
BM
248 * Note: Any objects accessed by the _REG methods will be automatically
249 * initialized, even if they contain executable AML (see the call to
250 * acpi_ns_initialize_objects below).
1da177e4
LT
251 */
252 if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
4be44fcd 253 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
b229cf92 254 "[Init] Executing _REG OpRegion methods\n"));
1da177e4 255
4be44fcd
LB
256 status = acpi_ev_initialize_op_regions();
257 if (ACPI_FAILURE(status)) {
258 return_ACPI_STATUS(status);
1da177e4
LT
259 }
260 }
261
7f0c826a
LM
262 /*
263 * Execute any module-level code that was detected during the table load
264 * phase. Although illegal since ACPI 2.0, there are many machines that
265 * contain this type of code. Each block of detected executable AML code
266 * outside of any control method is wrapped with a temporary control
267 * method object and placed on a global list. The methods on this list
268 * are executed below.
269 */
270 acpi_ns_exec_module_code_list();
271
1da177e4 272 /*
96db255c
BM
273 * Initialize the objects that remain uninitialized. This runs the
274 * executable AML that may be part of the declaration of these objects:
275 * operation_regions, buffer_fields, Buffers, and Packages.
1da177e4
LT
276 */
277 if (!(flags & ACPI_NO_OBJECT_INIT)) {
4be44fcd
LB
278 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
279 "[Init] Completing Initialization of ACPI Objects\n"));
1da177e4 280
4be44fcd
LB
281 status = acpi_ns_initialize_objects();
282 if (ACPI_FAILURE(status)) {
283 return_ACPI_STATUS(status);
1da177e4
LT
284 }
285 }
286
287 /*
96db255c
BM
288 * Initialize all device objects in the namespace. This runs the device
289 * _STA and _INI methods.
1da177e4
LT
290 */
291 if (!(flags & ACPI_NO_DEVICE_INIT)) {
4be44fcd
LB
292 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
293 "[Init] Initializing ACPI Devices\n"));
1da177e4 294
4be44fcd
LB
295 status = acpi_ns_initialize_devices();
296 if (ACPI_FAILURE(status)) {
297 return_ACPI_STATUS(status);
1da177e4
LT
298 }
299 }
300
301 /*
302 * Empty the caches (delete the cached objects) on the assumption that
303 * the table load filled them up more than they will be at runtime --
304 * thus wasting non-paged memory.
305 */
4be44fcd 306 status = acpi_purge_cached_objects();
1da177e4
LT
307
308 acpi_gbl_startup_flags |= ACPI_INITIALIZED_OK;
4be44fcd 309 return_ACPI_STATUS(status);
1da177e4
LT
310}
311
8313524a
BM
312ACPI_EXPORT_SYMBOL(acpi_initialize_objects)
313
e20a679b 314#endif
1da177e4
LT
315/*******************************************************************************
316 *
317 * FUNCTION: acpi_terminate
318 *
319 * PARAMETERS: None
320 *
321 * RETURN: Status
322 *
2f977b36 323 * DESCRIPTION: Shutdown the ACPICA subsystem and release all resources.
1da177e4
LT
324 *
325 ******************************************************************************/
4be44fcd 326acpi_status acpi_terminate(void)
1da177e4 327{
4be44fcd 328 acpi_status status;
1da177e4 329
b229cf92 330 ACPI_FUNCTION_TRACE(acpi_terminate);
1da177e4 331
2f977b36
BM
332 /* Just exit if subsystem is already shutdown */
333
334 if (acpi_gbl_shutdown) {
335 ACPI_ERROR((AE_INFO, "ACPI Subsystem is already terminated"));
336 return_ACPI_STATUS(AE_OK);
337 }
338
339 /* Subsystem appears active, go ahead and shut it down */
340
341 acpi_gbl_shutdown = TRUE;
342 acpi_gbl_startup_flags = 0;
343 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Shutting down ACPI Subsystem\n"));
344
1da177e4
LT
345 /* Terminate the AML Debugger if present */
346
347 ACPI_DEBUGGER_EXEC(acpi_gbl_db_terminate_threads = TRUE);
348
349 /* Shutdown and free all resources */
350
4be44fcd 351 acpi_ut_subsystem_shutdown();
1da177e4
LT
352
353 /* Free the mutex objects */
354
4be44fcd 355 acpi_ut_mutex_terminate();
1da177e4
LT
356
357#ifdef ACPI_DEBUGGER
358
359 /* Shut down the debugger */
360
4be44fcd 361 acpi_db_terminate();
1da177e4
LT
362#endif
363
364 /* Now we can shutdown the OS-dependent layer */
365
4be44fcd
LB
366 status = acpi_os_terminate();
367 return_ACPI_STATUS(status);
1da177e4
LT
368}
369
8313524a 370ACPI_EXPORT_SYMBOL(acpi_terminate)
2f977b36 371
e20a679b 372#ifndef ACPI_ASL_COMPILER
1da177e4 373#ifdef ACPI_FUTURE_USAGE
44f6c012 374/*******************************************************************************
1da177e4
LT
375 *
376 * FUNCTION: acpi_subsystem_status
377 *
378 * PARAMETERS: None
379 *
380 * RETURN: Status of the ACPI subsystem
381 *
382 * DESCRIPTION: Other drivers that use the ACPI subsystem should call this
44f6c012
RM
383 * before making any other calls, to ensure the subsystem
384 * initialized successfully.
1da177e4 385 *
44f6c012 386 ******************************************************************************/
4be44fcd 387acpi_status acpi_subsystem_status(void)
1da177e4 388{
44f6c012 389
1da177e4
LT
390 if (acpi_gbl_startup_flags & ACPI_INITIALIZED_OK) {
391 return (AE_OK);
4be44fcd 392 } else {
1da177e4
LT
393 return (AE_ERROR);
394 }
395}
396
8313524a
BM
397ACPI_EXPORT_SYMBOL(acpi_subsystem_status)
398
44f6c012 399/*******************************************************************************
1da177e4
LT
400 *
401 * FUNCTION: acpi_get_system_info
402 *
44f6c012
RM
403 * PARAMETERS: out_buffer - A buffer to receive the resources for the
404 * device
1da177e4
LT
405 *
406 * RETURN: Status - the status of the call
407 *
408 * DESCRIPTION: This function is called to get information about the current
409 * state of the ACPI subsystem. It will return system information
410 * in the out_buffer.
411 *
412 * If the function fails an appropriate status will be returned
413 * and the value of out_buffer is undefined.
414 *
415 ******************************************************************************/
4be44fcd 416acpi_status acpi_get_system_info(struct acpi_buffer * out_buffer)
1da177e4 417{
4be44fcd
LB
418 struct acpi_system_info *info_ptr;
419 acpi_status status;
1da177e4 420
b229cf92 421 ACPI_FUNCTION_TRACE(acpi_get_system_info);
1da177e4
LT
422
423 /* Parameter validation */
424
4be44fcd
LB
425 status = acpi_ut_validate_buffer(out_buffer);
426 if (ACPI_FAILURE(status)) {
427 return_ACPI_STATUS(status);
1da177e4
LT
428 }
429
430 /* Validate/Allocate/Clear caller buffer */
431
4be44fcd
LB
432 status =
433 acpi_ut_initialize_buffer(out_buffer,
434 sizeof(struct acpi_system_info));
435 if (ACPI_FAILURE(status)) {
436 return_ACPI_STATUS(status);
1da177e4
LT
437 }
438
439 /*
440 * Populate the return buffer
441 */
4be44fcd 442 info_ptr = (struct acpi_system_info *)out_buffer->pointer;
1da177e4 443
4be44fcd 444 info_ptr->acpi_ca_version = ACPI_CA_VERSION;
1da177e4
LT
445
446 /* System flags (ACPI capabilities) */
447
4be44fcd 448 info_ptr->flags = ACPI_SYS_MODE_ACPI;
1da177e4
LT
449
450 /* Timer resolution - 24 or 32 bits */
451
f3d2e786 452 if (acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) {
1da177e4 453 info_ptr->timer_resolution = 24;
4be44fcd 454 } else {
1da177e4
LT
455 info_ptr->timer_resolution = 32;
456 }
457
458 /* Clear the reserved fields */
459
4be44fcd
LB
460 info_ptr->reserved1 = 0;
461 info_ptr->reserved2 = 0;
1da177e4
LT
462
463 /* Current debug levels */
464
4be44fcd
LB
465 info_ptr->debug_layer = acpi_dbg_layer;
466 info_ptr->debug_level = acpi_dbg_level;
1da177e4 467
4be44fcd 468 return_ACPI_STATUS(AE_OK);
1da177e4 469}
1da177e4 470
8313524a 471ACPI_EXPORT_SYMBOL(acpi_get_system_info)
1da177e4
LT
472
473/*****************************************************************************
474 *
475 * FUNCTION: acpi_install_initialization_handler
476 *
477 * PARAMETERS: Handler - Callback procedure
44f6c012 478 * Function - Not (currently) used, see below
1da177e4
LT
479 *
480 * RETURN: Status
481 *
482 * DESCRIPTION: Install an initialization handler
483 *
484 * TBD: When a second function is added, must save the Function also.
485 *
486 ****************************************************************************/
1da177e4 487acpi_status
4be44fcd 488acpi_install_initialization_handler(acpi_init_handler handler, u32 function)
1da177e4
LT
489{
490
491 if (!handler) {
492 return (AE_BAD_PARAMETER);
493 }
494
495 if (acpi_gbl_init_handler) {
496 return (AE_ALREADY_EXISTS);
497 }
498
499 acpi_gbl_init_handler = handler;
500 return AE_OK;
501}
502
8313524a 503ACPI_EXPORT_SYMBOL(acpi_install_initialization_handler)
4be44fcd 504#endif /* ACPI_FUTURE_USAGE */
b0ed7a91 505
1da177e4
LT
506/*****************************************************************************
507 *
508 * FUNCTION: acpi_purge_cached_objects
509 *
510 * PARAMETERS: None
511 *
512 * RETURN: Status
513 *
514 * DESCRIPTION: Empty all caches (delete the cached objects)
515 *
516 ****************************************************************************/
4be44fcd 517acpi_status acpi_purge_cached_objects(void)
1da177e4 518{
b229cf92 519 ACPI_FUNCTION_TRACE(acpi_purge_cached_objects);
1da177e4 520
4be44fcd
LB
521 (void)acpi_os_purge_cache(acpi_gbl_state_cache);
522 (void)acpi_os_purge_cache(acpi_gbl_operand_cache);
523 (void)acpi_os_purge_cache(acpi_gbl_ps_node_cache);
524 (void)acpi_os_purge_cache(acpi_gbl_ps_node_ext_cache);
525 return_ACPI_STATUS(AE_OK);
1da177e4 526}
8313524a
BM
527
528ACPI_EXPORT_SYMBOL(acpi_purge_cached_objects)
b0ed7a91
LM
529
530/*****************************************************************************
531 *
532 * FUNCTION: acpi_install_interface
533 *
534 * PARAMETERS: interface_name - The interface to install
535 *
536 * RETURN: Status
537 *
538 * DESCRIPTION: Install an _OSI interface to the global list
539 *
540 ****************************************************************************/
541acpi_status acpi_install_interface(acpi_string interface_name)
542{
543 acpi_status status;
544 struct acpi_interface_info *interface_info;
545
546 /* Parameter validation */
547
548 if (!interface_name || (ACPI_STRLEN(interface_name) == 0)) {
549 return (AE_BAD_PARAMETER);
550 }
551
552 (void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
553
554 /* Check if the interface name is already in the global list */
555
556 interface_info = acpi_ut_get_interface(interface_name);
557 if (interface_info) {
558 /*
559 * The interface already exists in the list. This is OK if the
560 * interface has been marked invalid -- just clear the bit.
561 */
562 if (interface_info->flags & ACPI_OSI_INVALID) {
563 interface_info->flags &= ~ACPI_OSI_INVALID;
564 status = AE_OK;
565 } else {
566 status = AE_ALREADY_EXISTS;
567 }
568 } else {
569 /* New interface name, install into the global list */
570
571 status = acpi_ut_install_interface(interface_name);
572 }
573
574 acpi_os_release_mutex(acpi_gbl_osi_mutex);
575 return (status);
576}
577
578ACPI_EXPORT_SYMBOL(acpi_install_interface)
579
580/*****************************************************************************
581 *
582 * FUNCTION: acpi_remove_interface
583 *
584 * PARAMETERS: interface_name - The interface to remove
585 *
586 * RETURN: Status
587 *
588 * DESCRIPTION: Remove an _OSI interface from the global list
589 *
590 ****************************************************************************/
591acpi_status acpi_remove_interface(acpi_string interface_name)
592{
593 acpi_status status;
594
595 /* Parameter validation */
596
597 if (!interface_name || (ACPI_STRLEN(interface_name) == 0)) {
598 return (AE_BAD_PARAMETER);
599 }
600
601 (void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
602
603 status = acpi_ut_remove_interface(interface_name);
604
605 acpi_os_release_mutex(acpi_gbl_osi_mutex);
606 return (status);
607}
608
609ACPI_EXPORT_SYMBOL(acpi_remove_interface)
610
611/*****************************************************************************
612 *
613 * FUNCTION: acpi_install_interface_handler
614 *
615 * PARAMETERS: Handler - The _OSI interface handler to install
616 * NULL means "remove existing handler"
617 *
618 * RETURN: Status
619 *
620 * DESCRIPTION: Install a handler for the predefined _OSI ACPI method.
621 * invoked during execution of the internal implementation of
622 * _OSI. A NULL handler simply removes any existing handler.
623 *
624 ****************************************************************************/
625acpi_status acpi_install_interface_handler(acpi_interface_handler handler)
626{
627 acpi_status status = AE_OK;
628
629 (void)acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
630
631 if (handler && acpi_gbl_interface_handler) {
632 status = AE_ALREADY_EXISTS;
633 } else {
634 acpi_gbl_interface_handler = handler;
635 }
636
637 acpi_os_release_mutex(acpi_gbl_osi_mutex);
638 return (status);
639}
640
641ACPI_EXPORT_SYMBOL(acpi_install_interface_handler)
642#endif /* !ACPI_ASL_COMPILER */